SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30351e16d5ad08fdff968d3a26824080da8a137666694131334195cc038fa99e' 
  AND token = 'QG5DZOKg3zHzwEK0IKFkK6hSsXaXaCGePPL/DAHvo6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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