SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '474366e439ec66d206d6a37214c6ff8cc2d51d6f5f1407d3833918a30940979e' 
  AND token = 'cJ1IN7SSoYPkeuxxANq1qZlBxtJvjYuuHtmb86FNOmY=' 
  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"
    }
  }
}