SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f22fe4f42f70f0cb31bf20a10c513749a54f821ee8578f70429693ae477111ac' 
  AND token = 'G97rlAkRs4nlNa0N3UOcLDdOgenSGRlSc/SLCeh7Cmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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