SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a5ad3451d88e59ee55641593f820e72a9f69ddb5578a0fa9a4475516857a99e' 
  AND token = 'vnhO603EPC+qTt5LUtPI0GUXoSfLj8vZb0xo2pro7DA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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