SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca0bd2a68fcefa61996a92aac7964773151972f63df60a11defb74a03893fd94' 
  AND token = 'rufdq1BNyAG/K5W2HLLZvgqlrZoFC+cxUkw8h/RA0Is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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