SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60816f1096ea174363d20bc8b52a3ecec2231193bf5072d371af47d713c34bd5' 
  AND token = 'KnJ41EQ98RYHZLKM23ruBKGk+mYNfiJOwjqL+wcm4mk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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