SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7269fb632caea3dd9d135269ea307fd50002f5ac7ab28ec0634df26d35b66582' 
  AND token = 'HY6if3Tu6+yoMM3Iy59YdaGT0qPFxIfxHl93pCWC9qs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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