SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd0dad30ee1977d2ac94a02e75b49f5083e7ffa2025d51fde6ad07b2739e7261' 
  AND token = 'AiG0xGIv/uy3cOLxmVDoUX06ey8L+EqQposWq8GmRhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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