SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b3b0812c04fe9202bf47ad48d7b0fa95b6df4598802c114c9ff15fb9cdc6045' 
  AND token = 'FbqaX3gla1SFPhACRgHvJdMZ/DGPg0SAr/zr6+8Qzoc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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