SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7e5cb501665db2daa96125ed07c94009500ebae0312fe0dfbbd397b89646340' 
  AND token = 'kh0gsgViAffzR87Kf6NdCEtt0/fRpZ+w3gl2Av1lHZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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