SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b7260592eccf4ebe4624985a5be242723dd94f3d0f4314a253dd1b3f1c05422' 
  AND token = 'JUaGUxg0sxwlpUPaCd0XZv+wQ1I3uk/nzpgDnvHUw68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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