SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34960c75a02ec8094d95551539b8bf5b4606fdf5ab4f06951c0102b9990bb0ff' 
  AND token = 'IitvvL686VbEQpDWku7r8gqUSwD2b4VG0vPNbUuOfSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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