SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bd4bff37e945c2f84a91651faa4dde8ebb577783590ce2a6a954502ca037df99' 
  AND token = 'd6VsM9RzCdfsQccVvVr2iwwOsqfQevYkFHEMDyo8A4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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