SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b19c600ebea7f7b1dc0728c93ef36233849612f6430b3dcd3c796a928a4c59f0' 
  AND token = 'ub6mX2NjMj8gh4OQ5qYKKIjjeqi0SRNaYctyGeTyRTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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