SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c0ccb6640eedcdfb777e44821a9228999c50ccbe75804618bda1671ad0702d1' 
  AND token = 'Q7EuBBbp6U/CS03V1IMj/6adC78PsC1Rsb/TNohlHow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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