SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '466ea3e80db8f629035d1fef54ac3bab36961f010329501d843b7114d331c67f' 
  AND token = 'n/Z0MTS6t5Ebdr3rJiPXNyxXvpfhmtwyLIKdeoeawxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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