SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b733f838a3c239a9fbef21b3a5519e4dab1e60eb33b89af39792d1dcafba2b0' 
  AND token = 'c7cFMvbh4/wea+hoEoyaT07+dTZskAk9GhyQTT4djkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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