SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22868bfc49941e7c105d33a8ca730b8e25299457e9eb6ca3c6bd7ccc5d8b3c09' 
  AND token = 'eRd7niv3ghH2LyyKxD+FSHy+VCHfdLDN0jAZjORHPcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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