SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c1cd8867e5a951bf57ad587a73aa0023fabda107b6fb5c6dd91a34150b5c7345' 
  AND token = 'bh+AZTVve2pEVQcmtrK52/eRr7eJgwcspIACjlIPJU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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