SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70c11e1a8274dced7c93d729f2e4d355425161a456603a05ac37d15947fac0cd' 
  AND token = '8PRXT6m2RO+f3D9MJDJF7hqEbA8HjAHLCqbbdWosWZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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