SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec54ee9939c6aa16669d6f7157ca8b0c719526a4dc34bb95c52e51931953e710' 
  AND token = 'THXvWJWrC0gu6gZes9uDz6IPD2bfZfo422ByO9OY9Ds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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