SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f36cf037f6d41381a326ba830e2ca6d6542e990f34167c25e861142da94dd31' 
  AND token = 'AuPGN9ejWV/FpvJjoUonbVxk/rI05QPtfjLpmNxHsGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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