SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73e25c15e70c7f25ffbb87eb6c2fd4ae43dddd9ac5ec4701ba59dd857be4997b' 
  AND token = 'nL8ihHExcbVMV0TjzKo8BWSNIdga0C5j4f2QM92tHwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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