SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4a581dc2e9c83b051303e23dcb39cb2f634d138433b6ba7a644f4575d748386' 
  AND token = 'FofrlxkAtnjhhx+OshzUqCK/sI71pSVuvrLHQ4gkcMY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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