SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c318fc1e72059461e468cf9952fdd1ef8dd31a35d77adf53cbfc46b9ede5e933' 
  AND token = 'GqQAGAFGFevz4KaMRt68Q1rdfTKboduuNeEBpALeG+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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