SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8001911b23e51277873149816306ff796e8d44e29eda478c6e3280f7273d6a30' 
  AND token = 'ggPeqz0XiDNYShtmeeubXEu4eZfJUTBCMM/FHNO5ivg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}