SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '915b53b32404338f2e440b678b9b87df50a8b45a5f606a9941098e1615206b9e' 
  AND token = 'wuS2VVMZqEcpSJmdM35/NBhmgDPLDO0yjeY5jfIFYao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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