SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42da86f56b0eabbecc1256c7e75e7b8877547b4763ad62bac0af92cbd5675690' 
  AND token = 'zn7LNjDOXJ/V/EfzChn5HKDWpllz/CtW3sqw6xgLHrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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