SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ba78a37473ee797171a79f5fb78b171fa7da5f201013584fad9dc565be7ead13' 
  AND token = 'Heo/59iNKIdv3McCJfJIe2Px1lQKU8ShbAQHjHs+rPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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