SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a553bf402dea11dde3f0ed517fa212180c58728cdcf450e2dafd8f034d3a648' 
  AND token = 'Oq2kl5xtllC5u5YN1jdR2XQyMfWrVcBQK4+sPhQgat4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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