SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2142f2c48e3c1c64fd947dfe92e960eeab3dba258d599e4ea58cb6efa74c9d50' 
  AND token = 'wIfyNEchqrYrk0JaQcZKYwelYnyCj0zhnhxVgCfSJ1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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