SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c7aafbde0ac2c200a29ece9976685a1fa5b66543a38e62e1bf05498bd529754' 
  AND token = 'M4kMpkexjNijXFyZWkvJ26HocvgK65JOecGGdGP1TJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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