SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed49db35189fe5cff2152470ce0b68b10682699480ac95e55ac910c30aed1c36' 
  AND token = 'WvxDtSMRtCsGxKFCJH0odVypwM8Zfsy9LQzrK0jelPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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