SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ee326869ee444f19c99b97090be60ac608335b1787b14f8f0961f561f4320d8' 
  AND token = '+A/I7Mvh37fM+G3aUPp769kmYoT250uDyh4xgCZPjHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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