SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ad20f9b3c49eb77272b15c21a74917817f0f425336d6585343803fc6e247899' 
  AND token = 'X0huQH/vZ+Ya7skDdUeHjrOao3A8KMCIWlET2MWU+u4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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