SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c055be4a1522ac6300ebed6ee87869c5fbf910fbe77814346d4f882218446c2' 
  AND token = 'thvlgxGggEY1Mar9RL07bY29y3faPDTCoM5TGOHcC84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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