SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2a2b6ded3d75102b24481827c9850432718daefad3b169c6f3756c8d381093e' 
  AND token = 'XctVyvzrjn++t/y9+rfR5AV8cJLawHVnVHBgxAhS1Z0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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