SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c84286b62e50533638c9bf8c87416630d688383c4889f20a54aa451f61e4dca9' 
  AND token = 'odLgqs5gr4HEVCUv12NJBOC/FwFYjdmkj+A0PThhyqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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