SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd3b32e0c134a2f5eececeabb92ab2061f520e0dc9547fda7fb17d142c750c66' 
  AND token = '+7pnf5RntprZ0q5dQ0JsZlB/H4WbzNu131npYA9PkCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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