SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47e4239835cb348b0b3a02ff1f41bfa31fd8b5714d9fb8b91ad586b9cc4cc0b8' 
  AND token = 'd3GpjsqS8vIeINvSDDqR+/x+6l7AvqqHuxvz/8p1adY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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