SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2c67e9fef5a37e167049f014375aa966168494b5070cec4323df7f40d8ec3f9' 
  AND token = 'JnNSTTTheUY0DH69cJ8UW6qQ0Njrk08mFl9iN1N58Ms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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