SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5f2dbf5421cee8d0f1f5cd4cb601363584160842f89eb2ca4354912e4b27cca' 
  AND token = 'cSa0rduc8hnkmdta5GFmXFhcLuO5K3ia9JIol8Szc0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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