SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f96bfa75fc7ceb80ab72488b74703e299544f14b4fab429235fd6dfeeffc213a' 
  AND token = 'R7VYSpGBDKgHiMLFztb/uJnkmSPOiV/du6Qn1cB/faI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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