SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0125ab62160c03b1003272b4f76cc19e3212e1acbb5d0eee02036740805ede32' 
  AND token = 'qSUge2LjtlumjBjmjKqsaLmpjzYJqNaUI4LOv7BizI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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