SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f348d0d48b76d51fed78e6339fb61a62c6022845a6ca1b79a22d45db33bf63e2' 
  AND token = '0OKBGkKO6GwW4HlxADpumhFbVUpBeYU9eY44YqGueZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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