SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '203398108563920bc6a80156f71362e136d1fc9079aa2de1eb4a14f071e8b3b8' 
  AND token = 'LDvA6t0Mk8a4JffCoR9ac18ANKd8YEMM8LnRL+SgcKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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