SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '714644ab1090438b3b675c89d480260937458a2499190bdda2245b0e8123a0e3' 
  AND token = 'aoP5dgzyWvtu2S2Eqi7snJtNRHRWiFlIxLJfQLafppA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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