SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3e1688ab2926e1c84b1dae48528a236c6ab9fdadd734f79fcfce440d0729146' 
  AND token = 'uyHmwzCfprzoFRJe1aRNizmhbv9xViHmnlu3nTVV0pU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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