SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f237f85d6286e3eef1a269251973e371b2e8dcc3a6f44c0700e97f75203b872' 
  AND token = 'nH09EtOLmKHCqEhrA29BYcB4dULBoHg4g6O5Msasyu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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