SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5dbd3205a5918c7f50ceab708a14d8670cd34552054061bbe08c96119579284' 
  AND token = 'ALLck+O49uuiA6nP7B7BsHpKS332cCe1SmwtZimmXs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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