SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edf5b31977e180c0c90f837479140ed49d4bc463b03094b17aa28845a29188a4' 
  AND token = 'Suu1FnQ3LCi1SiECVUUowRlwRWF+D6ueQ0cXCNGAE/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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