SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b2ca2e14bad9a40aabd41d470a2aa889ed26df659e37bf74712e61264954439' 
  AND token = 'W/iegpwFFojDkcqxqMJklmEMfZRxmDI6ShKiLQI+yoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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