SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd28ad1e6741d4aa8bc9d404a1d58ae901e1c2971aaf77da9dbc9c2a85f7ae15' 
  AND token = 'GbzbHCGSqzGlhCVE6WqzeiB1aHh3gmF0Tk1fhJlPKlA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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