SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '416f4303e3d90a8929f69150692bc40352dbb384edacff47cd0d51156b41872d' 
  AND token = 'W8FSjhUPEKzjQPg9EIsHM++Wyw9E8P6r9sYDCaevgJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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