SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '485cab7f571517b74cac157d9aeaa6a8d724c672617149101f9c8583ac55696d' 
  AND token = '5yxtMSSwH2H3tF2rpCF/5gzPAoHLx1EP+9Z9C2lAnh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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