SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfafe23ace8c8994b3bb12383cb45af33f3cb4754ab1d2bb8aac1ee6bc1e838d' 
  AND token = 'gtZqwyPzMcxTNTNu/2T8WdeXZ5gVFO0LPW6SL5VcDKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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