SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '70fecb93af55ab2150f3220c6b98f61dabbd2c83511272798b51888869ab6207' 
  AND token = '4/+9L/C1v2iC+VK1vCOozvbDJMjRLiXAsxj7zgCFw/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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