SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6a57abffec0d33484d58a539da88e1eed31569eb0c38ecf9815ae5717401912' 
  AND token = 'KN2Zzv6qu/WtGQsd3qeASLlZ9s0Rx7TLmeVG5WvUvKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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