SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac8a65c626fc88f3f2eddeeb086a9980bf2fc0c6f6f643bd928a553c1df8e158' 
  AND token = 'ZADuTKYuSbQ0qfKcICfRyspQloDkCAkUPMUt1MKt/as=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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