SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7262903db25244122bd14c887e58a10a9fd6d5e25953cfd7a9429604cccef3a0' 
  AND token = '0gU5Y9IOtLEi/KKOZwOVMDx99Q1D3FqC+P63z/fplJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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