SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e102d6558de3b3f211507ece98e2068a5c97e70ae2cf9a544f45288db8f7fb7' 
  AND token = 'XCp+hLKAhOl8vSlICaBS2b+mNvZWszbYGqA/nBasVSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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