SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f4d652567c7dd9433292b43ab7b6a3a7305742eb38a53a70db10790b7e3f1db' 
  AND token = '08v217Kb/+6hFEBDxCW6P2lUff2jmAgKYUP1aqyzpV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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