SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b10d0fa68134d6c1093c2bcc56f9bafa81b87af3bf9cacf8abc72f92a9e98993' 
  AND token = 'JdQ+uMpZx48/5LSnmBock/8aQ25hxI1+CjLYzXEisRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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