SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ad7e98583264742af6bb3ccccdea08d2ac20e89734286dd7cf7d75db4641317' 
  AND token = 'JbiRRRvaUOCk3NTayPiMfRZAVa0tQlqU35ibkk8JEjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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