SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '615e5fdfce5806d76a2339f292f774b1e083c443ab0056125cb741e859c3873a' 
  AND token = 'IRUN7kiFjhF/5BxsoVP3HCVBRMHGaZqBVMfTSG2qZIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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