SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c66f5e27b638de8dc17e0cc35572eac7ca09767698d093240567a79b46cc45' 
  AND token = 'KZCpPpax5QdSiQ5V2jwqQ11zj4Nr5yCjoVLSrrjEeME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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