SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d86186ec1e4953bbac1cdbcec22f41bb75ff85d2b104223d28c525889cd5531' 
  AND token = 'fbS6cchnPPqn7byho+WKOcnEZuj1fJvm6TIKJeEOS50=' 
  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"
    }
  }
}