SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9e103deb4d9cfe2df438145280299d91199b5d65a0940853141087b66ccb5264' 
  AND token = 'THeFjxFQxPwW6tvRnM+wj+iQspDO7AyUkK6/VhdW42c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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