SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cd3e4f586b23e450c7700e4c98d061c0da3c04b2980a1c5d83b0395307c4dd31' 
  AND token = 'DaK4lXNs50lszkpdbtBrMRvSHQ62gt8VNIAFZNO4+R8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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