SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cd2373b6b26968b5d6be95d055445fd4256d4abbb2260a9b43452b4cb7d78f7' 
  AND token = 'RE/AKDC9lcGzso3K/pH/LlUP/SWFr5ygwGC1H0GhRZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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