SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '436282e108f681c2c4db046fbc4af36181c6cef47b8de806f477032fd3371e38' 
  AND token = 'ehPowA0OSCvdKVmtjj7b709sy+/Tdes9t9dBWg/lNO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}