SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9178b7d45ac0bcd9cb2c076a6107061f356ec0a5e1d9af2691e4d52c222da91' 
  AND token = 'GCeKazKCy2QBeTbUo80fUfWN8g00VxyGKn8eYS5Br6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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