SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d35625a5081492692f1bd73ee6f16534a2d6cd0d206d1bc895bbca91fa8fd4b' 
  AND token = 'Q9sD3Vk2aEnOjhalP9v83AjTI672lCJDTSgSQIsAdjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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