SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2dde3f1a9b9d2d79dd438068d16ec929e317b40b7b5213a12650297b33bb3fa' 
  AND token = 'wgt7TBCruZS59pLK6yoKqHtSRhAvIK+fEsbPGjtmWOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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