SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04a7240431dca04385b2b50e60cad14d2fc3c46078dbef9665b639859b85dd3a' 
  AND token = 'l/LMhukEFfLwueBRD7CJlVZQwkvVLlAuD0GCzrmlAGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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