SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a8c655b32ea42a16746037e3f4128734618b9bedafd353f04681215c5435f47' 
  AND token = 'Iyl6v2KddszxcDUyA6sfuIo8UynQcj58Wye8PUyXM7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}