SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '385295ba058f2f0abbfb6331cd45a58cbf51b6dbdd364acb8b605b752e372194' 
  AND token = 't9Q6heRAMb+lk7Wgi7VF1G9oqrKj+OjT7UEkDYBV/Sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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