SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f370f74ac715d37f1cbec0a40e161771f8bf925086fbbb0e2a99d024a78164c2' 
  AND token = 'DyaslE7FyNJ3YEaR2nDSlm5nMZzXSgezVgbqw8UWToE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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